Acoustical sensors are attached to objects generating sound in various ways. Simple stethoscopes are hand-held against the skin of the patient using hand-force of the physician.
The VRIxp, an acoustic vibrations recorder manufactured by Deep Breeze Ltd., Or Akiva, Israel, uses vacuum suction to attach and hold an array of sensors to human skin. This method has the following disadvantages:                Issues with adhering to hairy skin due to vacuum leaks        Limited duration in which the sensors can remain on the skin due to potential hematoma        Requires a vacuum pump of a certain size and electrical needs in order to produce the required vacuum level.        The vacuum pump creates noise during operation        Leaks near the sensors location may create artificial noise which may affect the recorded sounds        The vacuum system in whole is exposed to leaks which may reduce the adherence strength        Detachment and re-attachment of sensors during the breathing cycle due to changes in vacuum levels may simulate false pathological sounds such as crackles (rales)        The overall cost of a vacuum system is high        The user is required to oversee that the vacuum system is in good performance during operation        
Other methods of adhering an array of sensors to the skin and having certain limitations may include:                Utilization of body weight laying over the sensors toward gravity A belt or a vest which is wrapped around the patients and presses the sensors to the skin.        
A main issue of acoustic transmission between sound vibration sensors (SVS) and sound generating object (SGO) is related to the passage of acoustic waves from the SGO to the SVS through an air layer. The difference in the three materials involved results in reflection and scatters of acoustic energy, causing loss of energy and echoes, resulting in poor acoustic detection quality. To overcome this problem, materials of the SVS are designed to have similar acoustic properties as the SGO. To overcome the air layer between the SGO and the SVS, an acoustic matching interface is commonly used. One such common example is ultrasound imaging in medical applications. The impedance matching material is a paste commonly known as ultrasound gel, such as Parker Aquasonic® 100 Ultrasound Transmission Gel, manufactured by Parker Laboratories, Inc. of Fairfield, N.J., USA. This gel replaces the air layer between the SGO and the SVS and reduces the acoustic reflection in the surfaces between the different materials.
These kinds of gel, provided in a form of paste, are inconvenient to use for three main reasons, explained in reference to the VRIxp:
1. The gel does not provide engagement characteristics to hold the SGO and the SVS together during the acoustic monitoring process. When using the VRIxp this creates a major inconvenience to the operator and might result in low quality accosting signal recording.
2. When the acoustic signal acquisition is completed, the gel needs to be wiped off the patient and the SVS. This causes inconvenience to the patient and additional work load to the operator of the RVIxp.
3. Remainders of gel might function as contamination carriers, carrying contamination from one patient to another. This requires disinfection of the SVS prior to usage with another patient, which creates yet additional load on the operator and still holds the risk of imperfect disinfection and cross-contamination.
It is the purpose of the present invention to provide methods and tools to improve the engagement of SVS to sound generating object, particularly to human tissue. These methods and tools provide considerable improvements for the three main issues associated with gel: (1) Engagement mechanism (2) Need for wiping off the gel (3) Risk of cross-contamination. The present invention also provides an efficient workflow for setting up acoustic monitoring.